Before the much-vaunted 'Three Amigos' summit even formally begins on Wednesday, Canada, the United States, and Mexico have already rattled off a string of agreements.

The tripartite conference between American President Barack Obama, Mexican President Enrique Peña Nieto and Prime Minister Justin Trudeau — who is hosting the affair — is the first time that Canada has played host to the annual summit in a decade, and comes as Donald Trump, the presumptive Republican nominee, takes sharper aim at the free trade deal that underpins continental cooperation.

By all accounts, though, the summit has already been pretty productive.

The three are planning to sign a pact to draw 50 percent of their electricity from renewable energy by 2025 — which is a bit moot for Canada, which already generates most of its power through "clean" sources — while Mexico has signed on to a methane-fighting climate pact that Ottawa and Washington already agreed to earlier this year.

Canada, meanwhile, has agreed to lift a visa requirement for Mexican citizens in exchange for Mexico's removal of trade barriers that prevented Canadian beef from entering the country.

The clean-energy pact promises to be big business for Canada, which is already setting itself up to be a huge clean energy exporter to the United States. Trudeau, when he was running for prime minister, repeatedly vowed to invest in clean energy infrastructure.

As of 2015, over 60 percent of Canada's electricity comes from hydropower, with other renewable sources amounting to about five percent.

Canada's energy surplus is worth about $4 billion in exports to the US each year, and that number is expected to grow significantly — especially thanks to agreements like the one that will be signed on Wednesday.

But while the three leaders, all of whom are self-styled progressives, might be in relative consensus on climate change mitigation, it's unclear just how much this summit can do to bring the three countries closer together.

With increasing focus on the human rights situation in Mexico, Amnesty International is calling on Obama and Trudeau to take a tough line on Peña Nieto when it comes to police violence and police corruption.

An Amnesty International report released to coincide with the summit accuses Mexican military and police personnel of employing sexual assault and torture against women in the state's jails.

"These women's stories paint an utterly shocking snapshot of the level of torture against women in Mexico, even by local standards. Sexual violence used as a form of torture seems to have become a routine part of interrogations," Erika Guevara-Rosas, Americas Director for the group, said in a press release.

Trudeau, in a joint press conference with Peña Nieto on Tuesday afternoon, said he and his Mexican counterpart "discussed the need to uphold human rights, advance democracy and the rule of law and ensure respect for diversity as well as the ways in which we can work together to achieve these important goals."

For Obama, this summit will be his last. If Republican presumptive nominee Donald Trump succeeds him, it might be the last Three Amigos, period. A Trump presidency would, if he's taken at his word, mean a shedding of the North American Free Trade Agreement (NAFTA) and the erecting of a wall on the Mexican border, for which Mexico would pick up the tab.

"They're so used to having their own way," Trump said of America's neighbors in a speech on Tuesday in which he vowed to renegotiate NAFTA.

"Not with Trump. They won't have their own way ... NAFTA was the worst trade deal in the history — it's, like, the history — of this country."

Those provocative acts are sure to turn Ottawa and Mexico City from friends to foes.

But even Democratic likely nominee Hillary Clinton has gone back-and-forth on whether she would ratify the Trans-Pacific Partnership (an agreement that Canada and Mexico have both pushed for) and whether she would re-open debate on NAFTA, the free-trade zone encompassing Canada, the US and Mexico.

Trudeau wouldn't comment directly on the anti-trade rhetoric that is appearing in the American election, except to say that "we've seen around the world many examples of protectionism, of concern, of stepping away from trade agreements and engagements like we're showcasing today, and I think it's important that allies and partners like Mexico and Canada work together to address the challenges we're facing together."

In advance of Obama's touch-down in Ottawa, huge sections of Ottawa have been closed to the public, with security dominating much of the capital's core.